Re: Idempotence and "Replication Insensitivity" are equivalent ?

Chris Smith wrote:
> <pamelafluente_at_libero.it> wrote:> > For some reason some of you guys want to stick to a definition that is> > proving to be too strict, not even coerent since treat AVG and MEDIAN> > are treated differently (I have shown that conceptually they are both> > systesis of a distribution). Not practical.>> Pamela,>> Please reflect on what you're doing. You are coming into a newsgroup on> database theory (and then adding one on math; and yes, you added it);> and then telling us that you don't know anything about database theory;> and subsequently complaining that the standard formulation of aggregate> functions is wrong.

What is the standard formulation of aggregate functions ? Where can one
find such formulations (private attempts do not qualify) ?

> It's not wrong. It is widely known and accepted> that the median calculation fits poorly, if at all, into the category of> aggregate functions.

Do you have a reference for the non-acceptance of the median function ?
What about standard deviation ?

>You insist on acting like this result is an> invention of the people you are speakig to on this newsgroup; in fact,> it is probably older than I am.>> If you think that query languages should have a median function, and> that it should look just like an aggregate function, then fine. You can> choose a DBMS that does so, or even write a DBMS that does so if you are> so inclined. It remains true that your syntactic similarity has nothing> to do with aggregate functions, and that your implementation of the> function will look extremely different from a reasonable implementation> of any aggregate function.

What is a "reasonable implementation of any aggregate function" and
assuming there is such, what has the implementation got to do with the
abstract notion of aggregate function ?
Received on Sat Sep 23 2006 - 11:50:19 CDT